Fin Rot?

[Ziggy007]

I have 2 Black-Tailed Dascyllus that appear to have some damage to their dorsal fins. I do not have any other fish with anything like it. I have 6 Blue / Green Chromies, 3 Blue Damsels, 2 Lemon Damselfish, 13 hermit crabs, & 6 snails, 1 Cleaner Shrimp, and 3 Peppermint shrimp. All seem to be doing well except these 2 Black-Tailed Dascyllus. It also looks like just the Dorsal fins. Any Ideas out there?

Thanks, Ziggy

[leebca]

Hermit crabs are notorius for trying to nip at fish. Other fish do the same. If the tank is crowded (you don't say the size of your tank), it may encourage other fish to nip at them.

You think it may be fin rot, but are the edges of the newly missing fin part fuzzy white or clear. Clear is usually a sign of an attack.

[Ziggy007]

It's a 90 gallon Reef tank with 120lbs live rock, 60 lbs live sand and a 30 gallon sump. I am going to set up a Quarantine tank to see if they heal. The fins are kind of fuzzy white. Would a basic 10 gallon tank work for a QT?

Thanks for the reply!

[leebca]

Use these directions for the QT: A Fish Quarantine Process

It gives the procedure to determine the right size. It depends on the size and kind of fish and I don't know their size. But read through that post for quarantine info.

Separating the fish into QT is a very good idea. Obtain some fish antibiotic for treatment. The fuzzy look can be bacteria setting in. Any topical antibiotic for Gram negative bacteria is what you want, like Maracyn Two for saltwater fishes, or something like NITROFURAZONE (in the product, Furan-2) which is good for both Gram negative and Gram positive bacteria. Just follow the medication instructions.